General Brake master cylinder reservoir not playing

[lewey]

Evening. Have suffered from poor master cylinder seals for a bit too long now, so have been replacing the cylinder today. Almost done, but can't get the reservoir into the master cylinder. Should be a push fit of course. As far as I can tell, the rubber gromits are the same size as the old ones. If I extract one from the cylinder, it pops over an outlet on the reservoir easily enough. Any tricks anyone can advise me with? Any more pushing and the plastic will probably give way.

I should say that the cylinder is the more modern replacement item with all the outlets on the top, so has required bending of pipes to fit.

 

[panda-sport]

Are the distances between the two inlets the same between the old and new cylinder? It just needs a fraction to make the job a b....

 

[lewey]

Hear what you're saying, better get the calipers out and measure stuff. Probably should have checked before fitting everything else first. Now I'm stranded until I sort something out!

 

[lewey]

SORTED. The distance is the same between the inlets. The reason I hadn't measured this before is because the cylinders are blatently the same casting as is typical with other FIAT models in my experience. However, the gromits themselves have a 2mm internal diameter difference. Out with the new gromits, in with the old and hey presto, it slots in. Although I meight have solved this with a little persistance, I hope this thread might help others as the seals seems to be a common problem at the 15 year mark and the correct style master cylinder is not always easy to find now.

 

[Steven]

lewey, my 1989 750 is off the road at the minute as I've been unable to source a suitable master cylinder. The one I bought has the same mounting for the bulkhead but had different holes for the pipes/reservoir. What master cylinder did you use?

 

[lewey]

My opinion at the moment is to use any master cylinder that I think I can get the pipes into. They are all VERY similar, with just different outlets to suit the LHD, RHD, servo and non-servo markets. I have begun to question whether using any master cylinder with some pipe bending will be OK, especially when the master cylinders I keep seeing on eBay for servo models can be had for £1!

The replacement I am doing is on a early 1992 Bosch injection model. It HAD the rears brake pipe right into the end of the cylinder and the two front pipes going into a 'Y' adpater, secured on the top O/S. I assume this is the same for your car? NOW it has the rear entering TOP O/S toward the end of the cylinder and the two fronts with their own outlets O/S and nearside top respectively. The old reservior will go on fine despite three pipes entering on the top now. The front O/S pipe is a serious stretch to fit into it's new position, so I would say that ideally a new pipe needs making 2 inches longer. This is easy as it is the shortest pipe on the car and also easy to take out.

Post a picture of your cylinders or describe it. I should think you would be able to sort something out.

 

[Steven]

Mine is a 1989 non-injection model, I've attached a photo of the master cylinder currently fitted. It sounds the same, the rears into the end of the cylinder and the fronts into two pipes with a Y shape adaptor secured on the top with a bolt.

Jai found this on eBay, do you think it would be suitable?

http://cgi.ebay.co.uk/BRAKE-MASTER-CYLINDER-FIAT-UNO-PANDA_W0QQitemZ250180099755QQihZ015QQcategoryZ43120QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

[lewey]

Bled brakes this morning and they are great. Just as before but obviously better because of new fluid and good seals!

Your setup is exaclty the same as mine was as I suspected. I bought one of these style ones last week from a different seller and was a FIAT OEM part, but same design.

Shame that listing ended an hour ago as 3 were on offer for £0.99 each!

I obviously can't vouch for the one you pointed out, but it does look even better from a pipe bending point of view. The O/S front would go in the O/S side in almost the same fashion as it does at present into Y adapter. The othe pipes have loads of slack in my car, so would fit in anywhere really. Does the reservoir fit in though? Probably, but it is a different casting altogether.